Objectives: 1. Effects of Enovid in rodents; 2. In vitro viral effects of lymphocytes and fibroblasts; 3. Polyploidization of cells by Cytocalacin and its possible relationship in the induction of malignancies; 4. The value of aspiration cytology in the clinical management of thyroid gland diseases. Major findings: 1. All mice that were fed with Enovid pellets developed vaginal, cervical lesions consistent with severe epidermization suggestive of cancer. Experiments were repeated to produce the lesion for transplantation into two month-old mice. At the present time, approximately two months after transplantation, no definite growths have been observed yet. 2. Chromosomal damages on established fibroblasts by Herpes and Sendai viruses have been reported by several authors. Our pilot studies on cytomegalovirus demonstrated severe pulverization effects on chromosomes. The characteristics and extent of the damaging effect is presently under study. 3. Cytocalacin A, when added to established cell lines, induced bi- and multi- nucleation. However, we have not been able to maintain the multi- nucleated cells beyond four months. Vaginal smears of hamsters reveal cytological atypia after 4 months' paintings of the cervices with Cytocalacin A. No definitive malignant changes have been seen yet. 4. In the past year, 25 patients with cold thyroid nodules had aspiration cytology done. The aspiration diagnosis of these nodules ranged from positive readings of cancer (two patients), to Hashimoto's disease. Proposed course: 1. Continue to study chromosomal characteristics of viral infected cells. 2. Study in vitro different viral effects on established human cell lines. 3. Continue to study polyploidy of cells and its relationship to cancer.